This invention relates to improving mechanic safety while performing elevator maintenance.
Elevator mechanics are typically required to perform periodic maintenance that requires they be on top of the car. The mechanic is further required to operate the car from this position through a top of car inspection station 10, the front panel 12 of which is shown in FIG. 1. Elevators typically operate at speeds in the range of 0.5 to 9 m/s. These speeds would make it difficult for the mechanic to perform inspections or to position the car for maintenance. Therefore a slower inspection speed is provided in accordance with the governing safety regulations. In addition to operating the car at inspection speed the top of car inspection station provides the mechanic with sole control over car motion and makes the car unavailable to respond to calls.
The mechanic must access the top of the car by following prescribed safety procedures, which require the mechanic to press the stop switch 16 prior to stepping on top of the car. Once on top of the car the mechanic is required to place the car in the inspection mode by placing the inspection switch 14 in the inspection position 28.
To move the car the mechanic must first deactivate the stop switch 16, activate the common switch 18 then simultaneously activate either the car-up 20 or car-down switch 22 depending on the desired direction of travel.
The common switch 18 is provided to ensure that inadvertent activation of either the car-up or car-down switch alone does not cause unintended car motion. The stop switch 16 is provided to prevent any movement of the car not directed by the mechanic and is required to be activated whenever the car is not being moved.
However, the current practice requires the mechanic to remember to activate the stop switch 16. There is no signal or warning should the mechanic fail to activate the stop switch 16, which could lead to unanticipated movement of the elevator car, in the event of failure of the inspection mode circuit.
Objects of the invention include provision of an improved top of car inspection station that provides a signal indicating the stop switch is not activated whenever the car is in the inspection mode and is not being moved by the mechanic.
According to the present invention, the top of the car inspection station includes a warning circuit that includes an alarm that is activated whenever the mechanic fails to activate the stop button when not moving the car during inspection mode.